By Mel Bellar

I was listening to some talk radio (non-political!) while in the car the other day and heard a piece about “How Things Spread.” It was about ideas, people and disease but I, of course, immediately thought about plants, and unfortunately more about invasive species both vegetable and animal (hear me sigh as images of the emerald ash borer and Japanese knotweed flash in my head).

Plants spread in a variety of ways; after all, their sole purpose is to propagate and survive. Many of our most voracious spreaders do so through an underground root system called rhizomes. Some spread via roots that form from runners or branches that put out roots where they touch the ground and these are generally called stolons. Some plants will spread if a broken piece of stem is just deposited on top of the ground in a slightly moist area; Japanese knotweed operates this way (that is one reason why it is so successful in choking our stream banks). Then there are tubers and bulbs, which are underground organs or thickened parts that store energy and emit new buds or growth that can become new plants. These sometimes manage to get broken up and spread via critters or frost heaves and definitely by Homo sapiens.

The last significant propagation method, and the one I want to pontificate about today, is via seed, or specifically “volunteers.” Seeds are, of course, sewn by human, but what I am interested in is the seeds which take hold in the random, unplanned manner that nature uses. Seeds can travel far and wide via airborne mechanisms using fluff and kites, for instance, like dandelions and maples respectively, or they are clunky and just fall nearby the tree, like the apple, to work in a cliché.

Volunteers are both a curse and a blessing in the gardening world. When a thug reseeds prolifically we usually call it “taking over,” but when something we like reseeds or we have a pleasant surprise we call it a “volunteer.” I love volunteers and the way they add a more casual natural feel to the garden. Of course, you can’t leave them all (they require editing, which is what makes the difference between a garden and the wild) but they can greatly enhance the garden by providing free plants and design options. Another nice thing about volunteers is that they are usually quite happy in the spot they choose to grow and will probably do well in their elected spot.

One of my favorite volunteer stories in my own garden involves a sumac. I had tried to start a sumac grove on a client’s property; sumacs just don’t want to grow where you put them, although they seem to be happy in almost any sunny spot in the natural landscape. While I was trying to get sumacs to grow at my client’s, a single sumac seedling appeared at the bottom of some steps and a big stone wall in my garden. I left it (I like sumacs although many consider them to be weed trees) and now it is 20 feet tall and a prized fixture in my garden.

I have affection for numerous more common and generally welcome volunteers as well. Hollyhocks, lupines and fox glove are all reseeding biennials (although I think they are really just short-lived perennials) that have beautiful flowers and an old-fashioned appeal. Hollyhocks seem to pick inconvenient locations in my garden like at the edge of the path right next to the entrance arbor. I leave them anyway to add drama to the entrance. Rose campion may be a true biennial and it reseeds prolifically and in greater density creating nice waves of silver foliage with hot pink flowers. By the way, anything that reseeds likes to reseed in pea gravel. I have pea gravel paths in part of my garden, and it provides a cornucopia of seedlings that can be collected for transplanting. In addition to the already mentioned willing volunteers I get annual poppies, feverfew, black-eyed Susans, cone flowers, columbine, various sedums, European ginger and the occasional brunnera (Siberian bugloss).

Volunteers are an important part of my garden. I love the way the native columbine slowly drifts out from the source plant and creates a swath of the delicate red and yellow flowers that only nature could design. A couple of years ago a friend gave me one golden-leaved feverfew that generously spread in a couple of areas creating some bright spots throughout the season with its glowing foliage. Johnny Jump Ups add some detail and color in and around the paths and are easily pulled where they are not wanted. And last but not least (I almost forgot!) there are the two signature plants of my garden: sedum kamtschaticum (Russian Stonecrop) and Euphorbia myrsinites (donkey tail spurge). Both of these plants look great in and amongst rocks and walls and are great lining for paths where they tend to congregate. Next month I will talk about other types of spreaders.

Volunteering also applies to us as well and it would be something great to see spread. Get out there and volunteer in our community!~

Mel Bellar is the owner of Zone4 Landscapes and a passionate Andes gardener.